A group of small surgery centers in Denver and Colorado Springs has filed a federal lawsuit against HCA and Centura Health -- operators of Colorado's two largest hospital chains -- alleging antitrust violations and that they have tried to “monopolize the market for surgery procedures that do not require hospitalization in the Metro Denver market."

Named defendants in the suit, filed in U.S. District Court in Colorado, include HCA Inc., which owns HCA-HealthOne LLC's hospitals in Colorado, and Centura Health, a hospital operator co-sponsored by Catholic Health Initiatives and Adventist Health System.

The lawsuit, filed last Thursday, alleges HealthOne and Centura used their market share in an attempt to influence insurance companies "to discourage them from entering into contracts" with the independent surgery centers and that doctors who worked with the hospitals were discouraged from referring patients to the independent surgery centers.

"Consumer choices are limited when HealthOne, Centura and their co-conspirators attempt to run potential competitors out of business," the lawsuit states.

In a statement sent to the Denver Business Journal late Tuesday, Centura Health said it "is dedicated to improving health care value by focusing on outcome effectiveness, increasing service and convenience, and controlling costs. While we are still reviewing these allegations, we are confident Centura Health has not violated any federal or state laws and that our hospitals and other facilities are operating in the best interests of the communities we serve."

A call seeking comment from HealthOne has not yet been returned.

The plaintiffs claim that CASCA "has become dominated" by Centura and HealthOne, which also runs non-hospital surgery centers, and that it has since "joined the conspiracy" against the smaller centers, according to the complaint.

Not only were insurance companies discouraged from entering into contracts with the smaller centers, the lawsuit alleges, they "asked that the insurance company take actions against doctors who referred business" to a smaller center.

In at least one instance, the hospitals "refused to sign a transfer agreement with the Cherry Creek Surgery center in an effort to prevent Cherry Creek from having an on-going business," according to the lawsuit. The small centers are required to have transfer agreements in place in case there are any complications requiring hospitalization.

The lawsuit claims that surgery centers operated by the two hospital chains have allegedly engaged in “unfair business practices. . .related to copays and deductibles.”

Finally, in what the plaintiffs called “a blatant violation of the antitrust laws,” the hospitals allegedly held a meeting at CASCA Aug. 30 "with the majority of the major health insurance companies in the Denver and Colorado Springs markets, at which these defendants asked the health insurance companies ... to join them in concerted boycott of the Plaintiffs,"

No trial date has been set and the defendants as of late Tuesday had yet to file an answer to the complaint.